Antioxidant Activity and Chemical Composition of Colombian Propolis - Natural Antioxidants and Biocides from Wild Medicinal Plants - page 93

zones, this activity was the result of a differ-
ent chemical composition (Kujumgiev et al .,
1999). It is well known that biological activi-
ties of propolis are strongly related to their
chemical composition, and this is probably
the major problem when attempting to use
propolis as an ingredient in phytotherapy,
since the chemical composition depends on
the surrounding flora, harvest time, the col-
lection technique used and the bee species
that produce them (Pereira et al ., 2002).
The chemical composition and biologi-
cal activities of propolis have been studied
extensively in Europe and some countries of
America, especially in Brazil and Argentina.
As might be expected, the conclusion is evi-
dent: there are appreciable differences in
propolis' qualitative and quantitative com-
position, and this is strongly related to their
particular biological and pharmacological
properties (Bankova, 2009). Despite this,
there are limited studies on the chemical
composition and evaluation of biological
activities of Colombian propolis and this is
one of the reasons why we are interested in
the physical, chemical and biological char-
acterization of propolis from different
regions of Colombia that have not been stud-
ied previously.

during propolis' elaboration process
(Marcucci, 1995). Chemical studies of this
bee product have identified at least 300
compounds (Castro, 2001), including fla-
vonoids, aromatic acids and their esters,
aldehydes and ketones, fatty acids and
their esters, terpenes, steroids, amino
acids, polysaccharides, hydrocarbon com-
pounds, alcohols and many others present
in traces (Bankova et al ., 2000).
Due to the different uses and properties
reported for propolis, the medical, pharma-
ceutical, food and cosmetics industries have
been focused on this resinous substance. As
a consequence, it has caused the necessity
to create quality control and standardiza-
tion protocols for raw propolis and propolis
extracts. Many countries, such as Brazil
(Ministerio, 1999) and Argentina (Norma
IRAM-INTA, 2004), have developed differ-
ent methodologies to evaluate quality
parameters such as minimum soluble etha-
nol resin content (EEP) (30%), maximum
content of wax (40%) and insoluble residues
(25%), among others. Additionally, phe-
nolic compounds (5%) and flavonoids
(0.5%), which are commonly considered to
be responsible for biological activities, are
also analysed.
In our studies with propolis we have
evaluated some physicochemical parameters
for samples collected in the North (Atlantic
Department) and Andean (Antioquia Depart-
ment, South-west and Bajo Cauca sub-
regions) regions of Colombia. The results of
these analyses are shown in Table 7.1. Our
results are compared with international
standard values reported in Brazilian and
Argentinian regulations.
In the results obtained there are consid-
erable variations in humidity, ashes, EEP,
waxes and insoluble material content. For
most of the samples tested, the wax content
was the only parameter that is in compli-
ance with Brazilian and Argentinian regula-
tion values (less than 5%) (Ministerio, 1999;
Norma IRAM-INTA, 2004). Although raw
propolis samples showed low EEP values,
these extracts could present other different
types of bioactive principles in their com-
position with different biological proper-
ties that can confer them a quality status.

7.2 Physicochemical
Characterization of Propolis
from Colombia

The precise composition of raw propolis
varies with the source. It possesses a pleas-
ant aromatic smell and varies in colour,
depending on its source and age. Raw
propolis is generally composed of 50%
resins, 30% wax, 10% essential oils and
aromatic compounds, 5% pollen and 5%
other substances (Burdock, 1998). The
proportion of these types of substances
varies and depends on the place and
time of collection. Moreover, it has been
established that this chemical variability
depends on different factors, such as:
(i) exudates and bud from plants where bees
collect it; (ii) substances contained in bee
secretions; and (iii) materials introduced